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medical cannabis for bipolar disorder

Can Marijuana Help Your Bipolar Disorder?

Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

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Award-winning mental health journalist and author, John McManamy, wrote a thoughtful blog about the implications of medical marijuana as a treatment for bipolar. It’s reasonable to think that the risks outweigh any possible benefits, but the topic is certainly worth discussing.

Since both bipolar depression and mania can have psychotic features, there is some evidence that even medical marijuana use might have negative effects in people with bipolar disorder.  

Studies Show Links to Worse Outcomes

Medical research shows that cannabis use in people with psychosis is associated with an earlier age of their first psychotic episode. It’s also associated with manic symptoms and problems thinking.  

In one study, patients who quit using marijuana or reduced its use following their first psychotic episode had the greatest improvement in symptoms at the one-year mark, compared both to continuing cannabis users and people who had never used cannabis.   Long-term cannabis use may have a negative effect on long-term clinical outcomes for those with bipolar spectrum disorders, as well.

A 2015 study found lower bipolar disorder remission rates for current regular cannabis users (those who used it three times a week or more often) and those who regularly smoke tobacco when compared to people who don’t use either substance. That study, which lasted two years, concluded that regular marijuana users who also have bipolar didn’t do as well long-term as people who didn’t use the drug.  

Another study looked at the short-term effects of cannabis use in people with bipolar disorder and concluded that the drug was associated with both manic and depressive symptoms. However, that study couldn’t find evidence that people with bipolar were using cannabis to self-medicate on a regular basis.  

Now, none of these studies prove that cannabis is actually causing these problems in people with bipolar—they just show an association between marijuana use and problems. But you should factor this information into your thinking when deciding whether or not to use cannabis.

Substance Abuse Risk With Marijuana

All drugs have risks and side effects, and cannabis is no exception.

Substance abuse can be quite prevalent among those with bipolar disorder. People have used alcohol and drugs to try to control their systems in great numbers and may reduce their likelihood of successful treatment of their bipolar as a result.

By using marijuana to self-medicate for bipolar disorder, you run the risk of gaining a second diagnosis in addition to your bipolar diagnosis: substance abuse (Substance use disorder).

There's some interest in using marijuana to treat symptoms of bipolar disorder but the risks may outweigh any benefits.

Cannabis: Patients With Bipolar Should Avoid Use

David N. Osser, MD

Regardless of whatever short-term benefit patients perceive from cannabis, the evidence points clearly to an association between usage and worsening course of bipolar disorder over time.

We frequently encounter patients who use cannabis. More than 50 indications for medical marijuana are approved by various state governments, although no indications are FDA-approved. Marijuana is legal in 36 states-and 10 states allow recreational use-but regulation of the quality or purity of these products is minimal. Some patients are convinced that marijuana calms them, uplifts them, blunts their anxiety, enables them to sleep, and has other benefits like helping with pain. Many report that it is the only thing that is reliably helpful for neuropsychiatric symptoms, compared with prescribed medications. Notably, scores of nicotine users say the same thing: it is their coping strategy of choice for just about every stress or even their “only pleasure in life.” Others say the same things about benzodiazepines. Rhetorical question: What do these substances have in common?

Regardless of whatever short-term benefit patients perceive from cannabis, the evidence points clearly to an association between usage and worsening course of bipolar disorder over time. In a study of 4915 participants, Henquet et al. 1 found a strong increased risk of manic symptoms associated with cannabis over a three year follow-up (after controlling for possible covariates). They also saw an earlier age of onset of bipolar disorder, greater overall illness severity, more rapid cycling, poorer life functioning, and poorer adherence with prescribed treatments.

Zorrilla and colleagues 2 evaluated the subsequent course of patients with bipolar disorder who stopped cannabis use after an illness episode and compared their outcome with patients with bipolar disorder who had never used cannabis and a group that continued to use. The total sample included 1922 patients. In a two year period, the continued users had significantly lower rates of recovery, greater work impairment, and fewer were living with a partner. The data were based on patient reports; given that fact, there was likely under-reporting and probably an underestimate of the association between cannabis use and lives worsened. A systematic review of the effects of cannabis on mood and anxiety disorders confirmed a negative association between cannabis use and long-term outcomes. 3

Some patients exhibit psychotic symptoms after cannabis use. A recent study found that schizophrenia or bipolar disorder developed in many of these patients. 4 This happened in 47% of patients who became psychotic on cannabis over the next four years. This was the highest incidence of conversion after initial psychosis following use of various substances: the second highest was with amphetamine, at 32%. More patients converted to schizophrenia than to bipolar. As for any possible benefits, a recent review concluded that the evidence supporting use of cannabis for psychotic (or other psychiatric) disorders is “very low” and “inadequate.” 5

The non-psychiatric medical benefits of cannabis are also very thinly evidenced despite outsized claims to the contrary. 6 It is said to be “irresponsible” to encourage patients addicted to opiates to switch to cannabis for their problems with pain. 7

Thus, it seems that patients with bipolar disorder should stay away from cannabis in all its forms. Quitting cannabis should be on the short list of interventions if patients are not doing well. This is a tough sell in today’s political environment regarding cannabis legalization. Many newspaper editorials and politicians support its beneficial effects and use. Clinicians should not back down and accept patients’ insistence on using this product; rather, they should continue efforts to educate and to consider the problem to be a serious one that potentially interferes with otherwise appropriate and effective bipolar treatments that may be offered.

Disclosures:

Dr Osser is Associate Professor of Psychiatry, Harvard Medical School, and Consulting Psychiatrist, US Department of Veterans Affairs, National Telemental Health Center, Bipolar Disorders Telehealth Program, Brockton, MA.

References:

1. Henquet C, Krabbendam L, de Graaf R, et al. Cannabis use and expression of mania in the general population. J Affect Disord. 2006;95:103-110.

2. Zorrilla I, Aguado J, Jaro JM, et al. Cannabis and bipolar disorder: does quitting cannabis use during manic/mixed episodes improve clinical/functional outcomes? Acta Psychiatrica Scand. 2015;131:100-110.
3. Mammen G, Rueda S, Roerecke M, et al. Association of cannabis with long-term clinical symptoms in anxiety and mood disorders: a systematic review of prospective studies. J Clin Psychiatry. 2018;79:17r11839.

4. Starzer MSK, Nordentoft M, Hjorthoj C. Rates and predictors of conversion to schizophrenia or bipolar disorder following substance-induced psychosis. Am J Psychiatry. 2018;175:343-350.
5. Radhakrishnan R, Ranganathan M, D’Souza DC. Medical marijuana: what physicians need to know. J Clin Psychiatry. 2019;80:45-47.

6. Hill JH. Medical use of cannabis in 2019. JAMA. 2019;322:974-975.

7. Humphreys K, Saitz R. Should physicians recommend replacing opioids with cannabis? JAMA 2019; 321(7): 639-640.

Regardless of whatever short-term benefit patients perceive from cannabis, the evidence points clearly to an association between usage and worsening course of bipolar disorder over time. ]]>